Speed control device



Sept. 22, 1931. W, R, MURROW 1,824,292

SPEED CONTROL DEVICE Filed July 15, 1928 ATORNEY Patented` Sept. l22, 1931 UNITED STATES PATENT OFFICE WILLIAM R. MURROW, INDEPENDENCE, KANSAS, ASSIGNOR F ONE-HALF TO 0. W. COMPTON, 0F INDEPENDENCE, KANSAS SPEED coNTnoi. DEVICE Application led July 13,

My invention relates to speed controllingf devices and more particularly to devices of that character for limiting the speed of vehicles driven by internal combustion engines, the principal object of the invention being to automatically break an ignition circuit when the vehicle is operating at a predetermined speed and thus suspend firing of gases in a cylinder of the engine, whereby the piston in 1g. said cylinder will be prevented from influencing the crank shaft, and the driving force of the engine will be reduced or discontinued.

If all the cylinders are prevented from iiring while the vehicle is moving at said predetermined speed, unburnt fluids will accumulate in the cylinders and exhaust chambers and may pass to the crank and affect the lubricant therein; land when the ignition circuit is closed upon reduction of speed, the 29 unburnt excess gases in the cylinders and exhaust chambers may be exploded, with well known undesirable results.

It is therefore a further object of my invention td intermittently suspend the ignition 23 of gases while the vehicle is running at said predetermined speed, to alternate the firing of a group ofcylinders, andl to reduce without suspending the actuation of the motor, whereby the speed of the vehicle may be reduced without causing the accumulation of unburnt gases in cylinders or exhaust chambers.

In accomplishing these objects I have provided improved details of structure, the preferred forms of which are'illustrated in the accompanying drawings, whe-rein: A

Fig. 1 is a perspective view of a portion of an automobile equipped with my invention and partly broken away to illustrate con. struction.

Fig. 2 is a longitudinal central section of the device and portions of related elements of the vehicle. v

Fig. 3 is a plan view of the governor and shunting plate and la portion of the shaft on which the governor and plate are mounted.

Fig. 4 is a perspective view of the circuit shunting member.

Referring indetail to the drawings: 1 designates generally a motor vehicle hav- 1928. Serial No. 292,418.

ing a met-al frame 2, a dash 3, steering gear support 4, transmission housing 5, and em bodying an internal combustion motor 6 including a plurality of cylinders 7 provided with spark plugs energized by an electric circuit from a battery 8 grounded in the frame at 9.

A coil 10 is connected with the battery by a. line 11 in which is an ignition control switch 12 positioned on the steering gear support. The coil is connected to a distributor 13 by a line 14 and the distributor is connected tothe respective spark plugs.

A speed indicating device includes an indicator 15 positioned on the dash and a flexible saft 16 extending in a tubular housing 17, the housing having a coupling 18 on one end normally threadedly mounted on a threaded collar 19 lixed to the transmission housing and the shaft 16 having a key 20 on its inner end 21 for engaging a slotted stud 22 rotated from the transmission, whereby the `speed indicator is actuated in ordinary practice. v

Myl invention includes a housing 23 interposed between the Vtransmission and the indicator shaft 16, and a shaft 24 supported by the housing and coupled in series with the indicator shaft. The housing comprises a member 25 mounted on the collar 19 and a so member 26 including an end closure 27 pro-y vided with a threaded stud 28 on which the with the transmission stud 22 for rotation of the shaft from the transmission. The outer end 34 is 'tubular and slotted to receive the inner end 21 of the indicatorV shaft for rotating'the same. lBearings 36 arepreferably provided in a recess 37 in the closure 27 t0 support the outer ends' of the shaft 34.

Pivotally mounted on a spindle 38 extend- 100 ingtransversely in the shaft 24 is a centrifugally operating governor 39 including arms 40 having weights 41 at their outer ends which are freely movable in the housing.

Slidable on the shaft 24 is a block 42, and links 43 having outer ends pivotally mounted on a spindle 44,* extending through similar ends of the governor arms, are pivotally connected with the block by pins 45 and 46 extending from opposite sides of the block, whereby the block is rotated with and from the shaft and moved longitudinally of the shaft responsive to oscillating movements of the governor. A spring anchored on the governor-supporting spindle, tends to return the block to normal posi tion.4

Secured to the block and preferably integral therewith, is a commutator 48 comprising a conductive portion 49 and a non-conductive portion 50 and adapted to be moved by the governor into and out of engagement with contact oints or brushes 51 and 52 supported by t e housing for shunting ignition circuits, as presently described.

Each of the brushes 51 and 52 comprises preferably a smooth-wearing conductor such as carbon, of cylindrical form, slidable in a tubular member 53 of a threaded stem 54 adjustably mounted in an insulating bushing or brush holder which is supported in an aperture 56 of the housing closure, the brush being yieldingly supported in the tubular member 53 by a spring 57 anchored in the stem. v

The stems 54 are conductively connected to the ignition circuit by lines 58 and 59 eX- tending to a switch 60 mounted on the dash, and a line 61 connected to the coil and to the 'switchf The contact arm 62 rotatively-and conductively mounted on the post 63 with which the line 61 is connected, may be moved selectively into conductive relation with the line 58 or 59, to condition one or the other of the lines and shunting stems for controllingkthe ignition circuit.

The ignition circuit shunting brushes may be extendedv into the housing more yor less forsuitable 'spacing from the commutator to provide for contact therewith by the commutatorat predetermined speeds of the vehicle, and are fixed in'adjusted position by lock nuts 64.v Nuts 65 threaded on the outer ends ofthe stems are adapted to fastenthe lines 58 and 59 vconductively to the stems.

' The apertures 56 preferably comprise radially elongated slots in angularly extending portions 66 of the housing closure 27, and the bushings 55 have flanges 67 for engaging the inner face of the closure and are mounted in plates 68 which cover theslots and are slidable over the outer faces of the closure portions for adjusting the brushes radially of the commutator. Lock nuts 69 ix the 47 connected to the link and bushings xin adjusted position and cooperate with the ianges 67 to engage the bushings withV the housing. l

The commutator 48 preferably comprises a disk formed of conductive material and having a recess in its face in which thev non-conductive portion 50 is countersunk, screws 70 securing the inset insulating member to the isk. The insulating member inset in one side or semi-circle of the disk face, and varies from a perfect sector of the face, whereby a varying relation is effected between concentric circles on the face and V50 is preferably the arcs of said circles which lie on the insuf latin member. The outer portion 71 of the memer adjacent the periphery of the disk ispreferablynarrower than the inner portion 72, whereby the disparity between one of said circles and its insulator-overlying arc increases from the axis toward the periphery of the disk.

The disk Ais adapted to rotate in wiping engagement with the brushes for shunting the ignition circuit through the shaft and frame when the conductive face of the disk engages a circuit-connected brush, the shunting being interrupted when the lnsulator member passes in wiping contact with the brush. j

In operating the device the brush 51 may -be assumed to be adjusted to provide for shunting the ignition circuit and grounding it through the governor shaft and the frame when the speed of-the vehicle reaches 25 miles an hour, and the brush 52 to be adjusted for a limit of 40 miles an hour. The driver may set the switch 60, to condition the line 59 and shunting member 51 for functioning and when the governor causes thexcornmutator to contact the brush 51, the ignition circuit will be shorted'through theline 59 and governor shaft while the brush is in contact with the conductive portion of the disk surface and no cylinder will be fired while the ignition circuit is thus grounded. When the brush contacts the non-conductive member, theignition circuit will be again closed.

Because of the rapidity with which the disk rotates, the suspension of ignition will be only momentary, and the engagement of the brush with the non-conductive lmember 50 will permit the ignition circuit to operate normally for firing a cylinder during each revolution of the disk. Thus one or more cylinders will be fir d in a relatively short time during the maintenance of excessive speedof the vehicle, and in practice each cylinder will be fired approximately as often as each other cylinder, whereby accumulation of unburnt gases in the cylinders and exhaust chambers will be avoided'.

The cutting down of the number of igniting instances instead of the suspension of ioo ignition entirely, serves to reduce the speed of the vehicle graduall Should the driver esire to increase his speed limit, he may turn the switch 6() to condition the brush 52 for controlling the ignition circuit and the commutator will press the brush 51 inwardly of its tubular support and move into engagement with the brush/552l and close the circuit to the ground through the line 58.

The angular position of the portions 66 of the housing provide for angular position of the brush holders for convenient manipulation and projection of the brushes in diskcontacting positions.

A further means of adjustment is available in the radially movable engagement of the brush holders with the housing. A brush holder may be fixed in position adjacent the outer end of its slot, and the brush will then contact the disk adjacent its perlphery and will engage the relatively narrower portion of the non-conductive member, whereby the ground circuit will be broken for a relatively short time during each revolution of the brush-engaging disk, and relatively infrequent ignition incidents will occur while the vehicle is moving at the speed limit for which the brush is set.

When the brush holder is positioned adj acent the inner end of the slot, the brush will be adapted to contact the portion of the disk face, adjacent its axis yand the relatively wider portion of the insulating member; thus permitting a longer interval of normal firing operation of the circuit to the motor during each revolution of the disk. Radial adjustment of the brushes may therefore be made suitably to the type of motor, and to analogous conditions.

The switch may be moved to the position shown in Fig. l in which case neither of the shunting circuits will be conditioned for operation and the ignition circuit will function without interruption.

Radial adjustment of the brush holders may also be made for closer regulation of the speed of the vehicle, since more or fewer cylinders will be ired depending on the annular portion of the disk face with which the brushes come in contact, a greater number of impulses being given to the motor when the brushes are positioned for Contact with the relatively w1der portion of the insulating member.

It is apparent that the insulating member may have parallel side edges, or may taper towards either end, so long as it varies from the form and position of a sector of the disk face, to accomplish one of the purposes herein described, namely, variation in the length of ignition circuit closing periods by adjustment of the brushes. f

ters Patent is:

1. In a speed control device for a machine including a motor, a normally operative electrical -circuit controlling the motor, a normally open ground circuit connected to said first named circuit, and a governor, a rotating disk movable by said governor, a brush in said normally open circuit adjustable radially of the disk, said disk having a face engageable with said brush for closing said ground circuit, and a radial non-conductive member on said disk engageable with the brush upon rotation of the disk for breaking the ground circuit.

2. In combination with a multiple cylinder engine, of a motor driven vehicle, means for igniting charges in the engine cylinders including normally spaced commutator and brush members and means responsive to speed of the vehicle for moving one of said members toward the other, the commutator including a conductive element for breaking the ignition circuit engageable with the brush member at intervals out of time with periodic firing of the cylinders.

8. In combination with a multiple cylinder engine of a motor driven vehicle, and means for periodically igniting charges in the' engine cylinders including a normally operative electrical circuit, means controlling said circuit including a normally open circuit, spaced commutator and brush members, and means responsive to the speed of the vehicle for moving one of said members toward the v other, the commutator including a conductive element for closing the open circuit to break 1.

the first named circuit, and a non-conductive element comprising portions adapted to break the second named circuit at periodic intervals with reference tc the igniting periods for varying the periods of operation of 1 said igniting means..

4. In combination with a multiple cylinder engine of a motor driven vehicle, means operable at regular intervals for igniting charges in the engine cylinders including a normally operative ignition circuit and normally spaced commutator and-brush members, one of said members being grounded, and means responsive to speed of the vehicle for moving one of said members toward the other, a conductive element included in the commutator having portions engageable with ihe brush member at periodic intervals with reference to the igniting intervals for grounding the circuit.

5. In combination with a multiple cylinder engine of a motor driven vehicle, means for igniting charges in the engine cylinders including a normally closed electrical circuit, means controlling the circuit including conductive commutator and brush members, one of said members being grounded, and means responsive to a predetermined speed of the vehicle for moving one of said mem-` bers toward the other to ground said circuit,

means including a non-conductive element on the commutator for breaking said ground circuit, and means including an adjustable brush support for varying the intervals of ground circuit breaking at said predetermined speed of the vehic e.

\6. In combination with a support, a motor, a normally operative electrlcal circuit controlling the motor, and means controlling said circuit including a brush connected to said' circuit and a motor-actuated rotatable disk including a conductive element on one face and normally spaced from said brush and movable to engage said face with the brush for grounding the'eircuit in the support, means for limiting the lengths of grounding periods comprising a non-conductive element on said disk face interrupting said conductive element and having portions differentially related to annular paths on said disk face intersecting said portions7 and means for setting the brush to contact said face over a selected one of said paths for breaking the grounded circuit for a predeterilpined period during the rotation of the dis 7 In a device of the character described including a rotating shaft and a normally operative circuit, means controlling said cirv cuit including'a grounded rotating member adapted to be shifted into eective position responsively to the speed of said shaft having a surface forming a path provided With a non-conductive portion tapering transversely of said path, and a brush connected to said circuit engageable With said surface upon shifting movement of said member and adjustable transversely of said path to vary l the extent of engagement of the brush With said non-conductive portion upon each rotation of said member.

In testimony whereof I aiiiX my signature.

WILLIAM R. MUR-ROW. 

